Apparatus for the metal spray coating of tubes



July 13, 1954 I. H. MARANTZ APPARATUS FOR THE METAL SPRAY COATING OF TUBES Filed April 9', 1949 INTERNAL DRYING PAINTING UNIT UNT E l Q3 wsmvHoaw 033:4 EALUSOd WSINVHOBW 033d BALLISOd 3 Sheets-Sheet l METALLIZING WS\ NVHDBW 033d BALUSOd \NTERIOR BLOW OUT UNIT ROUGH ENING UN IT VAPOR DEG REASER lNVENTOR *[srael hula/anti ATTORN EYS EWZMMW,

y 13, 1954 1. H. MARANTZ 2,683, 6

APPARATUS FOR THE METAL SPRAY COATING OF TUBES Filed April 9, 1949 5 SheetsSheet 2 &

INVENTOR Aim e617 Mammy dad 3% #W ATTORNEYS Jfily 13, 1954 MARANTZ 2,683,436

APPARATUS FOR THE METAL SPRAY COATING OF TUBES Filed April 9, 1949 3 Sheets-Sheet 5 w 158 151 k A ATTORNEYS Patented July 13, 1 954 APPARATUS FOR THE METAL SPRAY COATING OF TUBES Israel H. Marantz, New York, N. Y., assignor to Columbia Cable & Electric Corporation, Brooklyn, N. Y., a corporation of New York Application April 9, 1949, Serial No. 86,532

2 Claims. 51

drying of the paint coating can be performed at a relatively high rate of speed without manual labor or waste of material, the cost of manufacture of the finished product may be excessive and not justified by the price at whichsuch tubes may be sold.

Where high temperature for long periods is resorted to for application of the metal outer coating, the outer surface of the tube may harden unduly and tend to crack or split, upon the bending frequently required in installation. A non-ierrous metal coating alloyed with the tube, such as an iron zinc alloy coating is less ductile and pliable than the tube itself and thus tends to crack or peel on especially in bending.

Where the metal coated surface of the tube is relatively smooth, it slips too readily in the hand and affords insufficient friction for application of the field bending tool, and does not readily afford a tight electric connection and so has a tendency to open too readily under vibration; moreover an outer coating of paint or the like will have inadequate adhesion upon such smooth metal coating and will readily crack or peel off such smooth tube, especially when bent.

While a pure non-ferrous metal coating may be applied by electroplating, the equipment and installation and the maintenance and power costs are high while the operation is relatively slow and results in'the objections above pointed out to a smooth coating.

It is a fundamental object of the invention to provide a substantially fully automatic, continuous, installation, expeditiously and reliably to convert the smooth steel tube as originally formed with lubricating grease, oil and grit adhering thereto and which is likely to become rusty, into a finished, interiorly and exteriorly degreased and cleaned and exteriorly roughened and metal sprayed and interiorly painted tube.

More specifically it is an object to provide an installation of low maintenance cost, automatically to remove the grease, oil, rust and grit from the metal tubes, to roughen the o'ute'rsurface thereof, to clean out the bore of the metal tube and uniformly to metal spray the exterior of such tube and then to paint the interior of such tube and dry such paint, which installation is capable of continuous operation at relatively high speed for long periods with a minimum of supervision, and the working parts of which are readily accessible for maintenance and repair.

Another object is to provide an installation for metal coating the outer surface of metal tubes without the use of high temperature for long periods of time and with consequent avoidance of the objections above pointed out to the surface hardening of the tube under heat; which coat is not of alloy character and avoids the objections oi peeling or cracking oii especially when the tube is bent and which coating is not so smooth that a coat of paint or of another metal thereon will tend to peel or crack oflf therefrom especially in bending the tube.

Another object is to provide a mechanism that may readily be incorporated in a continuously moving conveyor system, successively to remove such tubes from the'conveyor, clean the bores of the tubes and thereupon restore the tubes to said conveyor to be advanced thereby.

Another object is to provide a metal tube having a non-ferrous metal coating on the entire outer roughened surface thereof having a mat finish, which coating is of ductility and pliability no less than that of the metal tube covered thereby so that the tube may be bent without cracking or peeling off of the coating thereon.

In practicing the invention desirably, the following sequence is effected; lengths of metal tubes are passed through a degreasing unit and discharged in spaced relation upon a conveyor.

system which simultaneously rotates the tubes While advancing them lengthwise through a roughening unit which cleans ofi carbon and rust deposits and roughens the outer surface of such tubes. The roughened tubes are thereupon advanced in sequence by said conveyor system to a blowout unit which removes the tubes from the conveyor system to present such removed tubes to an air nozzle which discharges a jet of air therethrough and thereupon replaces such tubes upon the conveyor system to be advanced thereby to the metal spraying unit. For the metal sprayingoperation, means are provided positively to grip the tubes and simultaneously rotate and ad Vance the tubes at a controllable, relatively high rate of speed past metal spray guns which therefore deposit a uniform non-ferrous metal coating thereupon of any desired thickness. The sprayed tubes are thereupon conveyed to a painting unit and desirably presented thereto at an incline, which painting unit injects a quantity of paint into the bores of the tubes, the latter thereupon being rotated to distribute such paint upon the entire inner surface thereof. If desired, burnishing means may be provided between the spraying operation and painting operation to smooth slightly the roughened outer surface of the tube.

The finished article formed by such installation has a roughened outer surface with congealed non-ferrous metal particles thereon and completely covering such outer surface with a mat finish, the metal coating' being of ductility and pliability no less than that of the metal tube covered thereby, so that the latter may be bent without cracking or peeling off of the coating thereon.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. 1 is a diagrammatic view of the system, with parts broken away,

Fig. 2 is a diagrammatic cross sectional view taken along line 2--2 of Fig. 1,

Fig. 3 is a. diagrammatic perspective view of the blow-out unit,

Fig. 4 is a View similar to Fig. 2 taken along line 44 of Fig. 3,

Fig. 5 is a longitudinal cross sectional view taken along line 55 of Fig. 1,

Fig. 6 is a view similar to Fig. 2 taken along line E6 of Fig. 5,

Fig. 7 [is a view similar to Fig. 2 taken along line "1-1 of Fig. 1 and,

Fig. 8 is a view similar to Fig. 2 taken along line 8'8 of Fig. 1.

Referring now to the drawings in which is illustratively shown one embodiment of the invention, as diagrammatically shown in Fig. 1, the installation desirably comprises a plurality of operating stations which successively act upon the tubes to form the completed product.

These operating stations may include a vapor degreasing station A for removing lubricating grease or oils from the surface of the tube, a roughening station B for roughening and cleaning the outer surface of the tube, a blow-out station C for removing grit or dirt from the bore of the tube, a'metal spraying station D for applying a metal coating to the exterior of the tube and a painting station E for coating the interior of the tube, suitable mechanism being provided at each of said stations to perform the required operation.

In order successivelyto advance the tubes from station A to station D, a conveyor F is provided which may include a sequence of continuously rotating skew rollers, or, if desired, a positive feed mechanism G. However such positive feed mechanism G is preferred to advance the tubes through the metal spraying station to the painting station E. Suitable conveyor means I-I remove the tubes from the painting station and act upon such, tubes in order equally to distribute and dry the paint on the inner surface thereof.

If desired, burnishing station I having positive feed mechanism G associated therewith and, if desired, positive feed mechanism G may be interposed between the outlet of the metal spraying station D and the internal painting station to act upon the outer surface of the tubes and reduce the roughness thereof, and transfer means J may be provided to receive the tube from positive feed mechanism G to present it to the painting station E.

Having thus described the general outline of the machine, the specific component elements thereof will now be described in detail.

Vapor degreasing station A Here the grease or oil and incidentally much of the grit is, in part, automatically removed and in part converted into carbon black still adherent to the tubes. Though the degreasing instrumentality may be of any of numerous possible types, a particularly desirable arrangement is that diagrammatically shown in Figs. 1 and 2.

i A tall rectangular degreasing tank I i has. preferably a partition l2 across its width, illustratively of approximately one-third the height of the tank, dividing it into two substantially identical compartments !3 and Hi charged with a suitable liquid grease removing solvent such as trichlorethylene. Vertical conveyors l5 and It are disposed at opposite sides of partition 52 and each extend substantially the height and width of tank H.

As shown in Figs. 1 and 2 each vertical conveyor l5 and ['6 may comprise two pair of vertically-aligned continuously driven rollers l9 and H, one pair of rollers at each side of the tank, respectively near the bottom and top thereof. Each pair of vertically aligned rollers is connected by an endless belt 22 which has a plurality of equally spaced carrying fingers 23, extending from the outer face thereof at substantially right angles thereto. Although the fingers 23 of each pair of endless belts 22 of each of said conveyors l5 and [6 could be transversely aligned, those on one belt are desirably in advance of those on the other as shown in Fig. 1, so that when a metal tube 24 is positioned on each associated pair of fingers on the two belts of the conveyor I 5 in the manner hereinafter described, the metal tube 24 will be supported at a slight inclination as shown.

To feed such metal tubes 24 onto conveyor l5 as from a source of supply (not shown), an inclined table 25 maybe provided rigid with and extending transversely across the upper edge 25 of the wall 2! of the tank H. In order to release the metal tubes 24 one at a time from table 25 so that they may successively be discharged onto successive pairs of associated fingers 23 of conveyor l5, upstanding stop means 28 are provided adjacent the lower portion 29 of inclined table 25. Such stop means maycomprise a ledge extending transversely across the face of table 25. Means are desirably provided associated with said stop 28 to lift the lowermost metal tube 24 on the inclined table 25 over stop 28 so that it may slide onto fingers 23. Such means may comprise a pair of normally retracted plungers 3| on each side of table 25 respectively and transversely aligned thereacross. Each plunger may have an inclined upper facefiz adapted to extend through an opening 33 in said table 25 beneath the lowermost metal tube 2& that is restrained by stop 28. Actuating means 34 of any suitable type are associated with each of the plungers 3| to raise and lower the latter, whereby when the plunger 3I is raised it will lift said lowermost tube 24 which will slide oil the inclined face 32 over stop 28 onto the associated pair of carrying fingers 23 of conveyor l5.

As the conveyors l5 and i6 are both driven in a counterclockwise direction, as shown in Fig. 2, conveyor l5 will first carry the tubes 24 on successive pairs of associated fingers 23 in a downward direction.

In order to provide for continuous advance of the tubes, even when they reach the bottom of the tank II in which position the carrying fingers 23 will extend vertically downward, a curved plate 36 may be aifixed across the bottom of the tank, concentrically with the bottom rollers 2| of each of the conveyors I5 and I5 and spaced therefrom by little more than the length of fingers 23 as shown. Thus, as'the direction of travel of the endless belts 22 changes from a downward direction to an upward direction, as the fingers 23 for instance, reach vertically downward position, the tube 24 carried thereby will slide downwardly therefrom against the curved plate 36, and will then be picked up by the next pair of fingers 23 Thus the tubes are successively immersed in and lifted out of the degreasing bath in compartment I3.

As the tubes on conveyor I5 are advanced in an upward direction and start to emerge from the compartment I3, they will be successively transferred to conveyor I6. For such transfer a pusher device is employed which may comprise a pair of transversely aligned arms 38, one on each side of the tank, pivoted at their upper ends as at 39 and weighted at their free ends as at 4I. Thus as the topmost tube 24 on conveyor I5 abuts against arms 38, it will be pushed thereby outwardly on the associated carrying fingers 23 against partition I2, the upward movement of the fingers 23 at the same time pivoting arms 38. As the movement of the conveyor I5 finally raises the tube 24 above the upper edge 42 of the partition I2 the weighted pivoted arms 38 will be free to move toward partition I2 thereby pushing tube 24 over said upper edge onto an associated pair of fingers 23 on conveyor I6. At the same time the arms 38 will abut against the next succeeding tube 24 on conveyor I5 for the next transfer operation. Conveyor I5 will carry the tubes thereon through the relatively clean degreasing bath in compartment I4, and then through the vapor zone 3'! above compartment I4 until the uppermost tube 24 on conveyor I6 abuts against the pivoted arms 43 of a second pusher device. As the construction and operation of the arms 43 is identical to that of the arms 38, they need not be further described and will function in similar manner to discharge successive degreased tubes onto a downwardly inclined chute or guide 44 which directs the tubes onto conveyor system F.

As the metal tubes have desirably been retained at a slight inclination as they pass through the degreasing tank II, the solvent therein may readily drain from the bore of such tubes as they successively are lifted out of the bath in compartment I4 and through the vapor zone 31, and because of the heat of the bath and the vapor zone, the tubes will be heated Sllffiiciently to dry the same.

Although the chute or guide 44 could be of any one of a number of constructions, including conveyor belts similar to those of conveyors I5 and I6, it illustratively comprises a downwardly inclined table or plate 45, the upper edge 46 of which is afiixed to the upper edge of wall 40 of the tank I I and extends transversely thereacross. Desirably associated with each of the lateral edges of table 45 are inwardly extending flanges 4! extending parallel to and spaced from table 45 which flanges retain the tubes on table 45 as they slide down the latter. To conserve space, a second inclined table 48 is desirably provided at the end of flanges 41 extendin at right angles thereto toward wall 40. Table 48 also desirably has associated therewith at each of the lateral edges thereof inwardly extending flanges 49 extending parallel to and spaced from table 48.

In order to prevent the inclined metal tubes from jamming in the chute 44 as they slide down the latter, means are desirably provided to position such tubes so that they will be at right angles to their path of movement down the chute. Such means may comprise a pair of retractable plungers 55 positioned respectively on table 45 near the upper edge thereof and transversely aligned thereacross, each of said plungers 5B normally projecting through an opening 50 in such table 45. Thus when a metal tube 24 is discharged at an inclination from conveyor I6 it will slide against projecting plungers 55 and hence be positioned at right angles to its path of movement down the chute. In order to release the tube retained against such plungers 50, actuating means 5I are provided, illustratively similar to actuating means 34 previously described, and positioned beneath table 45 to retract such plungers 58.

As diagrammatically shown in Fig. 2 the lower edge of table 48 has an upstanding stop 53 which may comprise a ledge extendin transversely across such lower edge and against which the lowermost tube 24 in the chute will abut. Means are desirably provided associated with said stop 53 to lift the lowermost metaltube 24" on table 48, over stop 53 so that one tube at a time may be ejected from the chute onto conveyor F. Such means may comprise a pair of normally retracted plungers 54 on each side of table 48 respectively, and transversely aligned thereacross, Each plunger may have an inclined top face 55 adapted to extend through a corresponding opening 56 in table 48 beneath tube 24". Actuating means 51, which may be similar to actuatin means 34 previously described, are associated with the plungers to raise and lower the latter, whereby when plungers 54 are raised they will lift such lowermost tube 24" which will slide off the inclined face 55 of the plunger, over stop 53, onto the conveyor F.

The tubes thus passed through the degreaser in direction at right angles to their length are desirably next propelled lengthwise in sequence for the roughening operation which follows degeasing.

For this purpose, as illustratively shown in Figs. 1 and 2, the plurality of skew rollers SI of conveyor system F desirably lie in the same plane extending along a line parallel to the lower edge 62 of table 48, parallel to each other and at an angle to such line. The skew rollers 6| function in conventional manner, that is, when they are rotated in a clockwise direction as shown in Fig. 3, they will simultaneously rotate and advance the metal tubes thereon.

In order that tubes 24 may be fed one at a time to the skew roller conveyor system F and be slightly spaced lengthwise thereon, the speed of rotation of conveyors I5 and I6 and of conveyor system F, and the operation of actuating means 34, 5| and 51 must be properly correlated and it is therefore essential that they operate in proper timed relation with the movement of such conveyors. To this end a timer 83 is desirably provided, which is illustratively shown positioned above tank H and having a trip arm 64 actuated as by the fingers 223 of conveyor L5 as they are successively advanced. The timer is connected by suitable means (not shown) to the actuating means 3Q, 55 and iii so that they will respectively feed a tube into the degreasing machine, release a tube down the chute and eject a tube onto conveyor system F in properly timed sequence.

Roughening station B In order to clean the outer surface of the metal tubes, that is to remove residues of degreaser and carbon deposit therefrom as it is advanced by the skew roller conveyor system F, and also to roughen said surface, the tubes are passed through a roughening station E. Although any suitable means may be used to roughen the outer surface of the tubes such as chemical or mechanical means, illustratively mechanical means are used including a blasting unit ll which unit may be conventional in construction and so need be described but very briefly.

As the tubes are simultaneously rotated and advanced by conveyor system F, abrasive material. is hurled thereagainst by the centrifugal rotor E2 thereabove supplied from hopper thereby to insure effective cleaning and uniform roughening of the entire outer surface of each tube. A housing l4 encompassing that portion of the skew roller conveyor system F below rotor f2 collects the abrasive material and the particles removed thereby from the tubes, from which housing the abrasive may be returned to hopper it by means of a suction system '15.

It is of course to be understood that other mechanical blasting means could be used such as a jet designed to hurl abrasive particles against the tubes. Although one jet could be used a plurality are preferred to insure roughening of the entire surface of the tubes.

Tube bore blow-out station "(1 Since abrasive particles are likely to collect in the interior of the tube during its traverse through the roughening station, these are now removed by causing the skew roller conveyor system F to convey the tubes successively past the blow-out station C.

As diagrammatically and illustratively shown Figs. 3 and 4, the blowout mechanism may comprise a pair of guide members 11 and 18 illustratively in the form of J-shaped angle bars affixed in any suitable manner (not shown) so as to be parallel to each other and longitudinally spaced along the conveyor F, each of the legs 79, 8% of the guide members having a stop 82 at the upper end thereof. Desirably the angles 83 of the guide members are positioned slightly below and longitudinally aligned with the troughs 853 of the skew rollers ti so that clearance is afforded for the metal tubes as they are advanced by the skew roller conveyor F over the angles 83 of said guide members.

Vertically aligned with the angles of the guide members and positioned thereabove between the latter is a horizontal rod 84 rotatably mounted near each end in fixed bearings 85. Securely affixed to rod es and extending at right angles thereto are parallel fingers 88 and 81' each of such length that when in vertical position they will extend below the skew roller conveyor F and guide members 1?, l8.

Actuating means 88 are desirably associated with said rod to rotate the latter, to move the fingers thereon from the position shown in full lines in Fig. 4 to the position shown in dot and dash lines. Such means 88 may illustratively comprise a solenoid connected by suitable linkage 89 to rod 84 and controlled by a switch 9t affixed to an arm 9! pivotally mounted at its free end as at 92 so as normally to hang vertically at the end of the blow-out mechanism with the trip member 93 of the switch in the path of movement of the tubes as they are advanced by the skew roller conveyor F.

During the operation of the machine with a tube 24" in blow-out position as shown in Figs. 3 and l, as the metal tube 24 is advanced by the skew roller conveyor system F, the forward end of the tube 2& will abut against trip member 93 to close switch 90. Actuating member 88 through suitable connections (not shown) will thereby be energized to rotate rod 85 through linkage 89 and move the fingers 36, 81 in a clockwise direction from the position shown in full lines in Fig. 4 to the position shown in dot and dash lines. This movement will release tube 24 which will move down legs 8i of the guide members until it again rests on the skew roller conveyor system F and pick-up tube 24% which is restrained against forward movement by reason of its abutment against trip member 93, and move the tube 224 up legs "53 of guides ll and E8 until the tube 24 abuts against stops 82 as shown in dot and dash lines in Fig. 4 and closes switch 9% associated therewith and with guide Tl. At the same time the successive tube 24 is being advanced by the skew roller F toward trip member 93.

The closing of switch as energizes actuating means 98 which may be affixed for example, to the adjacent end is of the roughening unit ii and. which may comprise a solenoid having plunger it! associated therewith. The plunger is! desirably mounts a horizontal cross piece 182 at its outer end which carries at each end thereof respectively the ends of parallel horizontal pipes H33 and I94. Each of said ends extends through and is rigidly affixed to said cross piece and has a funnel-shaped member I85 amxed thereon. Members H35 are so positioned as to be coaxial with the tubes 2d when the latter are positioned against the longitudinally aligned stops 82 at the upper ends of the legs 59 or 8|.

The pipes Hi3 and U35 are slidably mounted in the end wall 99 of the roughening unit H with the inner ends of the pipes extending into the casing of such machine. A switch M35 is associated with cross arm M12, having a trip member it? in the path of movement of plunger it! of solenoid 93, which trip member when pressed by said plunger will energize solenoid 98 to retract plunger lill thereof.

Longitudinally aligned with funnels 505 at the other end of the blow-out mechanism are a pair of parallel reciprocable air nozzles E98 and 509 respectively which are to the rear of trip member 53 of pivoted switch Eli). The nozzles I88 and H29 control air Valves H6 and HI respectively, which valves are connected to a supply of compressed air desirably dehydrated (not shown),

by pipes H2 and H3. The nozzles which have a substantially flat face desirably with a resilient surface are so designed that when pressed they will open the associated valve to permit a jet of air to blow therethrough, a spring H4 being associated with each of said nozzles to retain them in valve closing position.

Energization of solenoid 98 will move plunger Nil thereof forward, carrying with it horizontal cross arm I02 affixed thereon and pipes H13, H14

and thereby advancing the tube 24 the end of which will be lodged in funnel I05, until the other end of said tube abuts against and advances air nozzle I98. This will cause air valve I I 8 to open to blow a jet of air through the tube 24 funnel I65 and pipe I03, to eject any parti cles in the bore of the tube into housing 14 of the roughening machine. As plunger IIJI reaches the forward end of its stroke it will abut against the trip member I81 of switch I86 which will close to again energize solenoid 98 which will now retract the plunger IIlI to move funnel I85 away from the end of tube 24 At this time tube 24 will have been advanced by the skew roller conveyor F so that its end abuts against trip member 93 to again close switch 90 thereby energizing actuating member 88 which will rotate rod 84 in a counterclockwise direction as shown in 4 to move fingers 86, 81 back to their original position shown in full lines. This movement will release tube 24 which will move down legs 19 of the guide members until it again rests on the skew roller conveyor system F and pick-up tube 24 to move it up legs '8I until it abuts against stops 82 at the upper ends of such legs to close switch 94 to repeat the blow-out operation previously described.

By reason of the fact that the trip finger 93 is in front of the nozzles I08, I09 as the tubes 24 move down the legs they will abut against the pivoted arm 9| to cam the latter to the side so that the tubes 24 will come to rest on skew roller conveyor F which will again simultaneously rotate and advance the tubes 24 for the next operation.

Metal spraying station "D After the metal tubes are blown out as heretofore described, they are successively fed through the metal sprawing station D which, as diagrammatically shown in Fig. 1, may comprise a chamber I28 having a plurality of conventional metal spray pistols I29 which though they may be of any suitable type, illustratively may be of the type known in the art as the Schori pistol. The pistols I29 are positioned so as to spray a non-ferrous metal coating such as zinc, aluminum, cadmium or the like on the tubes as they are successively advanced thereby, the tubes herein being described by way of illustration as being coated with zinc.

In order that the metal spray be equally distributed in a uniform layer over the entire outer surface of the tubes and that no area of the tube is exposed to the heated metal spray for any excessive length of time, it is desirable that the tubes be simultaneously advanced and rotated at uniform high speed as they are moved past the spray pistols.

Since the skew roller conveyor F effects but an impositive feed, a positive feed mechanism G is required for the spraying operation to assure advance and rotation of the tube at a controllable uniform high rate of speed to prevent the application of excessive heat to any portion of the tube or the application of a non-uniform coating thereon.

The positive feed mechanism G which is positioned between the output of the blow-out station and the input to the metal spraying station D is more fully shown in Figs. and 6 and comprises a housingIBI which may include a pair of parallel spaced end plates I32 and I33, illustratively circular asshown, between which are positioned a pair of, parallel, spaced side plates I34 and I35 illustratively-rectangular as 10 shown, extending at right angles to said end plates and rigid therewith.

End plates I32 and I33 have axial hubs I38 and I31 respectively in which are rigidly afiixed hollow shafts I38 and I39 respectively, rotatively mounted in bearings MI and I42 respectively, in turn rigidly supported in any suitable manner (not shown). 1

The bores of shafts I38 and I39 are of slightly larger diameter than, longitudinally aligned and coaxial with, the metal tubes 24 carried by the conveyor F, so that the tubes may be moved by such conveyor F into the flared mouth I46 of hollow shaft I38. The end I41 of shaft I38 which extends slightly beyond hub I36, is slightly spaced from the adjacent peripheries I48 and I49 of a pair of gripping rollers I 5| and I52 which are rotatively mounted respectively, as shown, on transversely aligned shafts I53 and I54 afiixed at each of their ends in the side plates I34 and I35 so as to retain said rollers in the same plane with their axes at right angles to the path of movement of such tubes on conveyor F.

The peripheries I48 and I49 of rollers I5I and I52 each desirably has a concave groove I50 therein in each of which a ring of resilient compressible material I55, such as rubber, may be aifixed.

The concave grooves I58 are spaced by a distance slightly greater than the outer diameter of metal tubes 24 and the resilient rings I55 are spaced by a distance slightly less than such outer diameter so that as the tube is pushed through shaft I38 by conveyor Fit will securely be gripped by the resilient rings.

Means are desirably provided to rotate rollers I5I and I 52 so that the tubes gripped therebetween will enter the flared mouth I51 of hollow shaft I39 and be advanced therethrough.

To this end each of the rollers I SI and I52 has a bevel gear I58 and I 59 associated therewith respectively and rigidly affixed thereto. The peripheries of such gears are engaged by a corresponding bevel gear NH and I62 rigidly affixed on the ends of horizontal shafts I63 and I64 respectively, journalled in and extending through associated bearing openings I65 and I66 in end wall I33.

The outer ends of the respective shafts I63, I 64 each has a spur gear I61 and I68 aflixed thereon whichspur gears mesh with a driving gear I1I rotatively mounted on hollow shaft I39, said driving gear I1I desirably having a sprocket wheel I12 rigid therewith operatively connected by means of a sprocket chain I13 to a sprocket wheel I14 upon drive shaft I15.

Thus, upon rotation of the driving gear I1I by the transmission from the drive shaft, spur gears I61 and I68 will be rotated in opposite direction to drive shafts I63 and I64 and through bevel gears I6I and I62 to drive bevel gears I58 and I59 and rollers I5I and I 52 thereon in opposite direction, thereby to advance the tube 24.

As driving gear HI and sprocket wheel I12 are rotatively mounted on shaft I39 their rotation will not rotate the shaft and hence the metal tube will only be advanced and not rotated. To rotate the tubes, a sprocket wheel I16 is rigidly afiixed to shaft I 39 and operatively connected by a sprocket chain I11 to a sprocket wheel I13 affixed on drive shaft I15.

Thus, upon rotation of said drive shaft I15, as hollowshaft I39 is rigidly aimed to the housing I35, the latter will be rotated to rotate the 11 tube 2d, while the rotation of the rollers l5! and it? will advance the metal tube.

By changing the size of the sprocket wheels it is a relatively simple matter to adjust the speed of rotation and advance of the metal tube.

Although with the installation herein described a non-ferrous coating of one metal is applied to the tubes, it is of course to be understood that two or more coats of the same or diverse metals could. be applied to the tubes or if desired a paint coating could be applied on a metal coating.

Burnishz'ng station I Where it is desired to smooth slightly the roughened surface of the metal tubes 24 after they emerge from the spraying station, a burnishing station I may be provided. This station may comprise a pair of circular wire brushes IBI and 582 having their peripheries almost in engagement and mounted in any suitable manner so as n to rotate desirably in a clockwise and counterclockwise direction respectively.

In order that the metal tubes may be positively gripped as they are advanced between the brushes Mai and I82 to be acted upon thereby, a positive feed mechanism G is desirably provided at the input of the burnishing station I and desirably, though not necessarily, a positive feed mechanism G is provided at the output of the burnishing station.

As the construction and operation of said mechanisms G and G is identical to that of positive feed mechanism G they need not be further described.

Painting station E The metal sprayed, and if desired, burnished tubes are then internally coated with suitable quick drying, flexible paint, lacquer or varnish. Although the tubes may be moved in lengthwise sequence through the painting station, for convenience they are moved not in lengthwise sequence, but at right angles to their lengths. The tubes to that end may be moved in such direction as they emerge from station D or I as the case may be, that is out of the plane of the sheet shown in Fig. 1. In a desirable installation that does not require an L-shaped floor lay-out as that just mentioned, the specific arrangement shown in Fig. 3. may beemployed.

as the metal tubes are advanced by positive feed mechanism G they may be discharged upon a pivoted transfer arm E83, having means associated therewith (not shown) to pivot the arm in a clockwise direction as shown in Fig.1 through i an arc of approximately 90 degrees to carry the outer end ofthe tube thereon up an inclined track l i i to the painting station E and after depositing such tube, pivoting back to its original position to receive the next tube.

This station may include a painting gun 135 registering with the upper end 536 of the inclined tube 2 5 and pushing means which illustratively comprises a solenoid l8! registering with the lower end I83 of the tube.

Although the painting gun Hidmay be of any suitable type, as shown in Fig. 7 it desirably comprises a tubular housing ldll having a plug it rigidly afiixed therein with a bore 9i therethrough of slightly larger diameter than the outer diameter of the tube 24.

Slidably mounted in the housing I89 is a disc shaped trigger member 592 having a bore 593 therethrough of smaller diameter than the outer diameter of the tube 24 and coaxial with the bore of plug [90, said bore i913 being outwardly flared at [94, I95. Trigger member I92 is normally retained against the end face 1% of plug i532 by coil spring [9! compressed between the end wall 952 of the housing E89 and the inner face 5% of the trigger member I92, the latter having a pin 2d! rigidly afiixed thereto at one end and extending longitudinally of housing ltd through an opening 262 in end wall 198.

Housing 39 mounts a paint nozzle 293 which comprises a tubular casing 202 rigidly affixed in end wall lad coaxial with bores HM and 193. The nose end 205 of casing 2% has a valve member 2M seated thereon and an actuating rod 2&8 aflixed at one end to the valve member Eel, is slidably mounted in a suitable bearing 2 ii in casing 204 and protrudes through the end wall 2E2 thereof.

By means of a coil spring 2l3 compressed between the inner face 2 of bearing 2H and a collar 215 aflixed on rod 2%, the latter is normally held in retracted position, thereby retaining the valve member 201 on its seat 2% to close the valve.

The rod may be actuated by suitable means such as a solenoid 216 affixed to the end 2!? thereof, which solenoid is controlled by a switch 2 l-B having a finger H9 in the path of movement of pin 20H.

To supply paint to the paint nozzle, a pressure chamber 22! is connected to the casing 2% by inlet pipe 222 and pipe 223 is connected to a source of paint (not shown) In the operation of the painting station, as the metal tube 24 is aligned with the painting head E85 and the solenoid i3! by the transfer arm I83, the solenoid l8? will momentarily be actuated to push the tube upwardly so that the upper end I85 thereof enters the bore of plug use and forces trigger member W2 and 2st forward against the resistance of spring lsl. When pin Zlliabuts against finger are of switch 213 the latter will close to actuate solenoid 2h; thereby advancing rod 298 to open the valve 25? and a fixed quantity of paint maintained under pressure in chamber 221 will be ejected into the tube 24.

As solenoid i8! is no longer energized at this time, coil spring I91 will quickly return trigger member 192 to eject tube 2 1 from the bore liii of plug I96 at the same time releasing switch 213 so that the valve member 2W will be reseated by spring 2l3.

The tube 24 will thereupon be picked up by conveyor system H so that the paint ejected therein may be distributed on the inner surface thereof in the manner hereinafter described.

The conveyor system H comprises an inclined substantially rectangular bed 23! having upstanding walls 232, 233 on each side thereof upon which the tubes 24 may rest. An endless conveyor belt 235 is desirably associated with each of said walls respectively, said belts having a plurality of spaced fingers 236 extending right angles thereto with transversely aligned pairs of fingers on said belts engaging successive tubes and movingthern along said walls 232,

Preferably the upper edges 2d! of the walls are roughened so that as the tubes are advanced thereon by the fingers 236 the tubes will rotate. This rotation in conjunction with the inclination of the tube on bed 23l causing the paint ejected in the tube to be equally distributed along the entire inner surface thereof.

The residual heat remaining in the tubes from spraying unit and the painting station.

the spraying operation will be suificient to hasten the drying of the paint and hence increase the efiiciency and rate of output of the installation. If desired, in order further to hasten the drying of the paint in the tubes, hot air blowers 242 and suction devices 243 may be positioned along each side of the bed, aligned with the bores of the tubes.

Thus, in but a few minutes after the paint is injected into the tubes, it will be equally distributed thereon and dried so thatthe completed tubes may be discharged from the conveyor H ready for inspection, labeling, packing and distribution.

It is also within the scope of the invention to interpose a blow-out unit between the metal If so located, the metal tubes on the conveyor may have their ends in close juxtaposition as they are passed through the spraying unit as the lengthwise spacing of the tubes which is required for the action of the blow-out uni-t would not be needed. Hence the number of tubes that could be passed through the spraying unit in a given period would be increased with a consequent increase in the output of the installation. However, with the blow-out unit away from the roughening unit, the particles discharged from the tubes would not be blown back into the roughening unit.

Although the illustrative embodiment of the invention herein described is designed to act upon one tube at a time, it is within the scope of the invention to act upon pairs of tubes as they are advanced through the installation.

To this end two tubes could be simultaneously discharged onto the conveyor F from the degreasing uni-t in which two or more tubes may be carried by each of the pairs of associated fingers of the conveyor 15 and It or, as shown and described herein, a single tube may be carried by each of the pairs of associated fingers. The conveyor F may thereupon carry the pair of tubes through the roughening station to be acted upon thereby, to the blow-out station which could be designed according to the principles set forth herein, to lift the two tubes simultaneously to present them to an air nozzle of sufficient width to accommodate the ends of the two tubes in order to discharge a jet of air through both tubes concurrently, whereupon such tubes are transferred to positive feed mechanisms to be passed through metal spraying units and subsequently deposited upon a transfer arm and conveyed thereby to the painting unit for injection of a quantity of paint into the bores of the tubes.

With the installation herein described, metal tubes may be degreased, roughened and cleaned, particles removed from the bore thereof, a metal coating of uniform thickness sprayed on the exterior of the tubes and painted on the interior thereof and dried all in a speedy, continuous operation without manual handling. As the heated metal particles from the spray guns are sprayed on the tube while it is being rapidly rotated and advanced, the particles will congeal rapidly and although the tube will become sufficiently heated to aid in the drying of the paint subsequently injected therein, no portion of the tube will be exposed to high temperature for any considerable period of time.

The resultant product thus has a roughened coating of pure non-ferrous metal, illustratively of zinc formed from the discrete particles sprayed thereon which congeal to completely cover the outer surface thereof with a mat finish and forming substantially an integral part of the tube and a coating of flexible paint on the inner surface thereof which coatings are ductile and pliable and will hence enable the tube to be bent without cracking of such coatings and especially of the outer coating which might cause rusting of the metal tube therebeneath.

By congealing is meant the conversion to the firm or relatively rigid non-flowable condition of the metal particles which emerge from the spray guns in fiowable or plastic state.

Although the installation above described has been shown as applied to relatively thin walled metal tubing, it is of course to be understood that it could just as readily be applied to metal tubing having regular pipe wall thickness.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. An installation of the character described for coating metal tubes, comprising a metal spraying unit having a fixed spray nozzle, means to grip and simultaneously and positively to rotate such tubes and advance the latter lengthwise through said metal spraying unit past said fixed spray nozzle to be acted upon thereby, whereby the entire outer surface of such tubes may be uniformly coated without any portion thereof being subjected to the action of said spraying unit for any excessive period of time, the means for gripping such tube and simultaneously rotating and advancing the same comprising a housing, means rotatably mounting said housing, a pair of rollers rotatably mounted in said housinglying in the same plane with their axes parallel to each other, said rollers having their peripheries spaced from each other and having gripping means thereon,

means to guide a tube into said housing between said rollers to be gripped thereby, drive means to rotate said rollers to advance the tube therebetween, means to guide such tube out of said housing from said rollers and drive means to rotate said housing.

2. An installation of the character described for coating metal tubes, comprising a metal spraying unit having a fixed spray nozzle, means to grip and simultaneously and positively to rotate such tubes and advance the latter lengthwise through said metal spraying unit past said fixed spray nozzle to be acted upon thereby, whereby the entire outer surface of such tubes may be uniformly coated without any portion thereof being subjected to the action of said spraying unit for any excessive period of time, the means for gripping such tube and simultaneously rotating and advancing the same comprising a housing having a pair of end plates, a pair of rollers rotatablymounted in said housing lying in the same plane with their axes parallel to each other, said rollers having their peripheries spaced from each other and having gripping means thereon, a pair of hollow axial shafts afiixed respectively in each of said end plates and extending into said housing, means rotatably mounting said hollow shafts, the inner ends of each of said hollow shafts being slightly spaced from the peripheries of said 15 rollers and longitudinally-aligned with a space therebetween, whereby'one of said hollow shaftsmay guide such tube into said housing between said rollers and the other of said hollow shafts may guide such'tube fromsaid rollers out of said housing, drive -means-operatively connected to References Cited in the file of this patent UNITED STATES! PATENTS Name Date Bernardin- July 13, 1909 Number Number 7 Name Date Robinson Mar. 8, Rosener et a1 July 8, Collins Oct. 39, Schifiner Apr. 21, McIlroy- June 15, Boax Nov. 16, Huebner Oct. 18, Whitfield et a1 June 4, Meduna May 25, Sneddor, Jr Oct. 31, Richards, Jr. Jan. 20, 

